Apparatus for adjusting the striking pin of a maltese cross mechanism



A. w. DE BRUYN 2,919,595 APPARATUS FOR ADJusTlNG THE STRIKING PIN 0F A MALTESE CRoss MECHANISM 2 Sheets-Sheet 1 Jan. 5, 1960 Filed Jan. 5, 1955 mm A f?. .IALIAAIAWIH nnbanu `Lem. 5, 1960 A. w. DE BRUYN APPARATUS FOR ADJUSTING THE STRIKING PIN OF A MALTESE CROSS MECHANISM 2 Sheets-Sheet 2 Filed Jan. 5, 1955 INVENTOR AUGUST WILLEM DEBRUYN MGNT Unit-.ed SfaS Patent() APPARATUS FOR ADJUSTING THE STRIKING PIN OF A MALTESE CROSS MECHANISM AugustWillem de Bruyn, Emmasingel, Eindhoven, Netherlands, assignor, by mesne assignments, to North American Philips Company, Inc., New York, NX., a

corporation of Delaware Application January 5 1955, Serial No. 480,043

Claims priority, application Netherlands February 26, 1954 1 claim. (ci. 'I4-39s) The invention relates to a method of adjusting the striking pin in a Maltese cross mechanism. It has been found in practice that it is not possible to machine the striking pin and the slots 'in the Maltese cross with which the striking pin cooperates, in a manner such that an accurate cooperation between the striking pin and the Maltese cross is ensured. Divergences of a few microns in the shape of the striking p in and/or of the slots produce, during operation, a disturbing sound each time the striking pin engages a slot of the Maltese cross.

For the adjustment of the striking pin it is already known to provide an eccentric journalling of the pin shaft and the Maltese cross shaft, the relative positions of these shafts being variable during operation until the troublesome sound has reached a minimum. How ever, this adjusting method can be carried out only if there is a sutcient amount of play between the periphery of the locking disc and the Maltese cross. In general, the correct position of the striking pin obtained by this known method will result in an incorrect position of the locking disc relative to the Maltese cross.

The invention has for its object to mitigate the aforesaid disadvantage. According to the invention the striking pin is rotated eccentrically about its longitudinal axis in the bearing. The position of the striking pin can thus be varied independently of the relative positions of the pin shaft and the Maltese cross shaft, so that both the striking pin and the locking disc may be positioned correctly with respect to the Maltese cross. It is advisable to adjust first the locking disc relatively to the Maltese cross and then the striking pin relatively to this cross. With the inverse order the adjustment of the locking disc relative to the Maltese cross would annul the correct adjustment of the striking pin. The striking pin may be journalled in this case in its bearing with such an amount of friction that its position in the bearing is maintained during operation.

The method according to the invention requires, in general, that the Maltese cross should not be driven for adjusting the striking pin.

The striking pin is preferably rotated in a conventional manner by means of its bearing and the position of the striking pin relative to its bearing is determined by means, which are also rotated, the speed of rotation being usually equal to the speed of rotation of the bearing, the speed of rotation of `the bearing or of the means being variable for a short time, so that the means can be adjusted relatively to the bearing and hence the striking pin relatively to the Maltese cross. The. striking pin can thus be adjusted whilst it drives the Maltese cross. Thus in a simple manner that position of the striking pin can be found at which the sound is a minimum. During the adjustment of the striking pin a continuous variation of the sound volume is thus obtained, so that the minimum canv be readily determined.

In all these cases, particular measures must be taken 4at the striking pin shaft and want of space in the' Maltese 2,919,595 Patented Jan. 5, 1960 cross mechanism renders the incorporation of the aforesaid means diftcult. According to a further aspect of the invention, the striking pin shaft is hollow and the means are constituted by an adjusting shaft coupled with the striking pin and journalled in the pin shaft. Thus, owing to 'their centraly position the means occupy as little space as possible. The pin shaft and the means may be driven each by a synchronous motor, in accordance with a further aspect of the invention, one of the stators being rotatable about the shaft of the associated rotor. lBy rotating the stator the striking pin is turned in its bearing in the Maltese cross mechanism driven with its operational speed.

The invention also relates to a device for adjusting a striking pin in a Maltese cross mechanism and to the Maltese cross mechanism adjustable by carrying out the invention.

With reference to a few figures, which are to be considered as examples of possible embodiments, the invention will be described more fully.

Fig. l is a plan view of a device according to the invention for adjusting a striking pin in a Maltese cross mechanism to be used in a lm projector.

Fig. 2 is a view and partly a sectional view of a striking-pin shaft with the strinking pin according to the invention and Fig. 3 is a lateral view of the device shown in Fig. 2.

Fig. 4 is a front elevational view of the striking pin assembly as seen from the left of Fig. 2.

Fig. 1 shows a Maltese cross mechanism 1, comprising a shaft 2, on which a quadruple Maltese cross 3 is seated and a striking-pin shaft or support 4, on which a striking pin 5 is seated. The striking pin is journalled in a disc 6, which serves at the same time in the coniventional manner for arresting the Maltese cross 3, as long as the striking pin 5 does not engage it. The striking pin is rotatable about its axis and about a shaft which is eccentric relative to the axis of the pin. This eccentric position is shown on an enlarged scale in Fig. 4. The friction with which the striking pin is rotatable in the disc 6 is variable, since a bearing 7 is conical and supports a conical part of the pin 5. The striking pin is also rotatable about the conical bearing 7. By means of a nut 8 the pin may be drawn into its bearing 7 with the desired force. To the striking pin 5 is secured a segment 9 (see Figs. 2 and 3), provided with teeth 10, which engage teeth 11 of an adjusting shaft 12. As clearly seen in Fig. 4, the shaft 2.3 is eccentric relative to the shaft 5.

Both the striking pin shaft 4 and the adjusting shaft 12 are provided with a rope disc 13 and 14 respectively,

each of which can be coupled by ropes (not shown) with a motor 15 and 16 respectively. The stator of the motor 16 is rotatable about the shaft 17 of the rotor, since the housing 18 is provided with disc-shaped bodies 19, which are seated fxedly on annular bodies 20 secured to the device. By rotating the housing 18 the adjusting shaft 12 is turned relatively to the striking pin shaft. This displacement is transferred by the segment 9 to the striking pin 5, which is thus rotated in its bearing 7.

The striking pin is adjusted as follows. The entire Maltese cross mechanism 1 is provided with the pulley 13. The adjusting shaft 12 is introduced into the hollow pin shaft 4 to an extent such that the teeth 11 engage the teeth 10 of the segment 9. The motors 15 and 16 are switched on and rotate in synchronisrm sov that the pin shaft 4 and the adjusting shaft 12 rotate with entirely equal speeds. 4 ,V

The housing 18 is rotated slowly` about the shaft 17 of the associated rotor, so that the striking pin turns in its bearing 7. In the position of the housing 18, at which the sound is at a minimum, the housing 18 is xed and the adjusting shaft 12 is drawn to the right, so that it is disengaged from the toothed r'im 9 and then the motors 15 and 16 are stopped. The striking pin is drawn tight with the aid of the nut 8 or (see Fig. 2) secured to the disc 6 by means of bolts 21 and 22, after which the Maltese c'ross mechanism 1 can be removed from the device.

What is claimed is:

A device for adjusting a striking pin in a Maltese cross mechanism comprising a striking pin support, means mounting said support for rotation, a conical bearing contained in said support, a striking pin shaft, said shaft being mounted for rotation in said conical bearing, a striking pin mounted on said shaft and having its axis eccentric thereto, a gear segment, means securing said gear segment to said striking pin shaft, a removable adjusting shaft having gear teeth at one end thereof and being journalled in said striking pin support, said gear teeth on said adjusting shaft meshing with said gear segment, a control device for said Maltese cross mechanism including two synchronous motors, one of said motors being operatively connected to said striking pin support to rotate said support, and the other of said motors being operatively connected to said adjusting shaft to rotate said adjusting shaft, said latter motor having a rotatable stator whereby rotation of said stator causes further rotation of said adjusting shaft and said striking pin eccentrically about Kthe axis of the striking pin shaft by means of the gear connection therebetween.

References Cited in the le of this patent UNITED STATES PATENTS 1,503,793 Kershaw Aug. 5, 1924 

